E71 Man-Made Thing Belongs to versions: Version 6.0Scope Note: This class comprises discrete, identifiable man-made items that are documented as single units.
E25 Man-Made Feature Belongs to versions: Version 6.0Scope Note: This class comprises physical features that are purposely created by human activity, such as scratches, artificial caves, artificial water channels, etc.
E22 Man-Made Object Belongs to versions: Version 6.0Scope Note: This class comprises physical objects purposely created by human activity.
E18 Physical Thing Belongs to versions: Version 6.0Scope Note: This class comprises all persistent physical items with a relatively stable form, man-made or natural.